Some people have suggested that if states disqualify Trump from the ballot, other states will retaliate by targeting Democratic candidates from the ballot.
I think this is a dumb argument.
Certainly some people in various states will try to do so. The retaliatory effort is almost certain. But they will have to show some actual evidence of constitutionally disqualifying behaviour for their state courts to take their arguments seriously.
Just as multiple Republican, even Trump, appointed judges rejected challenges to Biden's electoral victory because the people filing the suits came to their court without anything resembling actual evidence, state supreme court justices (even if not every lower state court judge, where the quality can vary wildly) will take the legal requirements seriously.
So unless challengers can find some plausible evidence disqualifying a Democratic candidate, those suits will be tossed quicker than the cookies of a toddler on a merry-go-round.